Dragon Age: Inquisition's move to an open-world environment is something that the team at BioWare has "wanted to do for a long time", but was limited by technology.

"Now we've switched to Frostbite 3, it's really opened up things like streaming volumes, where we can build these massive areas without completely blowing our budget pipe loading into that level," cinematic designer John Perry told Digital Spy.

The world of Thedas, however, is not strictly open from the beginning, with areas gated off by story progress and the growth of your Inquisition. The more you travel and influence you gain, the more you can explore.

Although every region is not accessible from the beginning, each one is teased to be vast in size: a "medium"-sized area was said to be bigger than the entirety of Dragon Age 2, with Inquisition itself the biggest world that BioWare has ever created.

As well as a core story, the world's deserts, snowy mountains and marshes will be populated with landmarks, from caves to outposts and ruins, allowing the player to explore off the beaten path and discover side-quests.

The opening of a rift sees beasts, such as powerful dragons, emerge and wreak havoc on the world below

There will also be key installations that can strengthen the Inquisition's efforts and influence, such as Keeps.

Once you've entered a Keep's gates - through secret tunnels, by having the rogue in your party sneak in or simply by brute force - and defeated everyone inside, it will be then added to your network.

Keeps can be assigned as espionage, political or military bases, and can also open up further opportunities in the area.

For example, rebuilding an ancient statue could raise troop morale, open up gates to other areas or use a nearby sulphur pit to boost your alchemy resources.

Another element teased in regions are dragons, which arrived with the opening of the rift. These beasts will often be sighted in the distance and, once your party is up the challenge, can be eventually fought.

Similar events in each region will encourage players to return to previous areas once they're at a high level or have more intel to fight them.

For example, smaller rifts dotted around the landscape have also opened up, and with it powerful demons, which can be beaten back and defeated for more experience.

Combat in Dragon Age: Inquisition has been described as "the best of both" Dragon Age: Origins and Dragon Age 2, with the return of the strategic, tactical mode alongside the more reactive, action-based combat from its sequel.

"I'd say it's much more similar to Dragon Age: Origins' combat, but with some of the improvements to the reactivity," Perry explained.

"I feel like when I hit this button, I perform this action, the guy reacts to it, the animations are a lot smoother. You'd have this real-time hybrid that you can engage with if you choose to.

"Giving you that range of interactivity or strategy with those combats, ultimately we've got the best of both worlds, which is really great. Some players like Dragon Age Origins, some like Dragon Age 2, but now you can pick which one you want to play."

Meanwhile, health will now no longer regenerate, and resources will become more scarce, resulting in a more challenging adventure that has players consider a whole dungeon's worth of encounters instead of a single fight.

"It really forces you to strategize," Perry said. "Who do I need to bring with me? I can only carry so many spells, so should I bring a healer or something like that. And if not, I'll double down on my potions.

"It really makes your focus on resource management, how you build your party, using their strengths to strategically mitigate that damage in those battles."

Like Mass Effect 3, those players who want to focus more on the story can alter the difficulty to concentrate on what they prefer.

However, for those that want it, the strategy is certainly there. By using thorough planning and taking all of your party's strengths into account, you can emerge from encounters unhurt, while destructible environments - such as wooden bridges - allow you to exploit structural weaknesses to win fights swiftly.

Like previous Dragon Age games, dialog choices and the success of your actions define what happens next, and will have a lasting impact on the story and relationships with those in your party.

One event shown was the fate of Crestwood, a village under attack by Red Templars, that has four or five possible outcomes that will help shape the type of leader you want to be.

The choice here is whether to go straight to the village and save its residents or defend the nearby Keep, strategically placed in a mountain nearby.

Opting for the latter option sees the enemy forces retreat, but results in every villager being burnt alive, much to the dismay of one of your party members.

Such difficult choices are set to be the bread and butter of Dragon Age: Inquisition, but it will also take into account the ones you made in previous games.

Since the game's release will straddle console generations, past choices will be delivered through a web-based service called Dragon Age: Keep.

Players must go through and set all of their decisions as they made in previous games. Although it could be considered a bind, it allow players to start over with different choices if they weren't satisfied the first time round.

It also allows players to switch to a different platform entirely. An Xbox 360 player can now jump to PC or PS4, for example, and their personal world of Thedas will go with them.

While prior actions will have repercussions big and small in Dragon Age: Inquisition, unlike Mass Effect, it won't need to take into account the smaller choices and actions - such as dialog with individual characters - because it once again has a new hero.

"It's been a bit easier for Dragon Age because every game has a different protagonist," Perry explained.

"The really big, world-changing events we'll certainly react to. A lot of your followers will certainly react to the events of Dragon Age 2. It's a lot easier for us [than Mass Effect] because we're not following the same protagonist.

"I really like that. You could consider the main character in each Dragon Age game as the world of Thadus, and really looking at this from these different perspectives. It gives us a lot of opportunity to do cool things to this world."

While Dragon Age: Inquisition will be coming to Xbox One, PS4 and PC, it will also appear on Xbox 360 and PS3. It won't have the graphical flourishes of the next-gen versions, but BioWare promises that the same vast open-world landscapes and strategic combat will remain intact.

Dragon Age: Inquisition will be available on Xbox One, PS4, Xbox 360, PS3 and PC in late 2014.